I want to implement "sign in with apple" feature for my webapp. Currently it's in developing phase so can i integrate it without paying to Apple Developer Program membership. As google auth platform provide it for free, so does apple?
You need to ask Apple and they do not respond here. Apple moved its developer forums earlier this year to the developer section of their web site:
and I believe it is a pay-for enrollment, but check. You question is not likely to get responses here because of that move, and the section your are in now, "Using the Communities" is titularly for asking how to use the forum software and, unfortunately, gets few views.
Testing Signup with Apple for free during app development
